Process of aerating and preserving milk.



No. 7I4,5l0. v /Pat nted Now-25. I902. n. a. NASH.

PROCESS OF AERATING AND PBESERVING MILK.

(Application filed Dec. 28, 1897.)

(No Iodel.)

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, UNITED STATES PATENT DFFICE- RICHARD GRAINGER NASH, OF- LUCAN, NEARDUBLIN, IRELAND.

PROCESS OF AERATING AND PRESERVING MILK.

To all whom it may concern;

Be it known that I, RICHARD GRAINGER NASH, a subject of Her Majesty theQueen of Great Britain and Ireland, residing at Finnstown House, Lucan,near Dublin, Ireland, have invented certain new and useful Improvementsin the Aeration and Preservation of Milk, (for which I have obtainedLetters Patent in Belgium, No. 130,850, dated September 25, 1897, andfor which I have applied for Letters Patent in Great Britain, No.14,209, to bear date June 26, 1896,) of which the following is aspecification.

This invention relates to an improved process of aerating and preservingmilk; and it consists in separately sterilizing the carbonicacid gas,oxygen, atmospheric air, or other gas employed in aerating and the milkprior to their commixtion, the bottled or decanted mixture being,moreover, subjected to treatment with a view to its completesterilization.

In the accompanying drawings, Figure 1 illustrates a diagrammatical viewof a series of appliances adapted for treating, milk according to myimproved method. Fig. 2 isa section of an alternative form of apparatusfor employment in finally heating and completing sterilization of thebottled or decanted mixture. 1

A is a heater; B, a separator; O, a cooler.

D is a receiver for gasor air.

E is an aerating-machine, and F a bottlingmachine.

Gis the apparatus employed for completing the sterilization of thebottled mixture.

According to myimproved method the milk, (which may be new milk, skimmedor separated milk or whey, but preferably separated milk,) to whichwater or other liquid may be added, is first partly sterilized byheating it in areceptacle A to a temperature of 156 to 160 Fahrenheit.The milk may then be again subjected to the action of a cream-separatorB and then cooled by means of the cooler 0, same consisting of a coilimmersed in ice or cold water or other suitable cooling appliance, thetemperature of the milk being hereby reduced to about l0" Fahrenheit.

The aerating-gas may be carbonic acid,oxy gen, air, or other suitablemedium. When carbonic acid is used as the aerating medium,

atent No. 714,510, dated November 25, 1902.

Serial No. 663,880. (No specimens.)

the gas having been produced by any known method, as at D, is sterilizedin the following manner: On leaving the generator D it is first causedto pass through a coil D containing any suitable purifying agent andwhich is maintained at a red heat in a closed chamber D. This coil Dmay, however, be heated by means of steam or by being immersed inboiling water. The gas is then cooled by causing the same to passthrough a coil D submerged in cold water in a tank D Any bacteriacontained in the gas being thus destroyed and any bad flavor or otherobjectionable qualities it may have possessed having been removed thegas is then washed by passing it through a bath D containing sterilizedwater or other suitable purifying liquid or substance D the quality ofthe gas being hereby further improved. The gas thus sterilized andwashed is then charged, by means'of a suitable aerating-machine or pumpE, into the milk, and the mixture is decanted or bottled with the aid ofa bottlingmachine F.

By treating the milk in the manner above described a large portion ofthe bacteria is destroyed, the curdling of the milk upon its coming intocontact with the gas is prevented, and any objectionable flavor the milkmay have possessed or acquired is removed. By adding soda, potash, orother suitable substance and sugar in the proper proportions-J01example, about one and onehalf drams of potash and three drams of sugarto each gallon of milk-I find curdling of the mixture is prevented, andif sterilized water in the proportion of about one quart of water toeach gallon of milk be added the flavor of the mixture is improved andrendered similar to the ordinary soda and milk mixture.

If it be desired to impart a flavor to the milk, the flavoring matter,which may be in any convenient form, such as an essence, is preferablyadded to the sterilized water D in the bath or tank D to be taken up bythe gas ing forced into the milk. In place of or in addition to theflavoring matter an alkali, such as bicarbonate of soda, may be added,the alkali acting as a corrective of any acid tendency in the milk.Instead of flavoring the in its passage therethrough prior to the gasbe- IOO gas on its passage through the sterilized water the aerating-gasmay be passed through or over the flavoring-essence. The flavoringmatter or essence may in some instances be added to the milk; but I havefound that when adding some flavoring matters to the milk instead of tothe gas the tendency has been to cnrdle the milk. Under certaincircumstances this mode of procedure is therefore unadvisable. Ifdesired, a suitable quantity of sugar may be added to the milk.

In order to produce a creamy head on the aerated milk, and thus toimprove its appearance when served for consumption, a suitable essence,such as commonly employed in the manufacture of aerated waters, may beadded. If not already flavored as previously described, a little gingeror other flavoring-essence may be added to the milk before bottling.

The charged bottles containing the sterilized and aerated mixture areplaced in a bath G, containing water, which is raised by suitable meansto a temperature of about 160 Fahrenheit for about thirty minutes andcooled as quickly as possible for the purpose of completing the processof sterilization. The heating of the bath may be effected by passingsteam or hot water therein by means of the pipe G, the cooling beingaccomplished by shutting off the flow of steam or hot Water andadmitting cold water into the bath by means of the same pipe, the latterbeing provided with a two-way cock for use in effecting the desiredobject. The bottles are contained on trays H, furnished with handles forfacilitating their insertion in and removal from the vessel and aresupported by transverse bars 72 or brackets. g is an overflowpipe.

The completion of the sterilization of the mixture may, however, becarried out in a jacketed vessel G, to which steam is admitted by way ofthe pipe G, and wherein the temperature is raised, say, to 150 or 212Fahrenheit or thereabout, the charged bottles being maintained at thistemperature for one hour or thereabout. The steam is then shut off andthe contents of the vessel cooled by supplying cold water to the jacketG by means of the pipe G g g are drain-pipes for the interior of thevessel and the jacket, respectively.

The temperatures and duration of heating at any of the stages may bevaried to suit requirements, as also the pressure at which the bottlingis effected. In hot weather, or if the mixture be required forconsumption in hot climates, the water in the bath maybe raised to atemperature of about 212 Fahrenheit for about twenty minutes, thetemperature being then lowered to Fahrenheit or thereabout. After aninterval the temperature is again raised to about 212 Fahrenheit forabout twenty minutes and then lowered as quickly as possible.

If the mixture be required for keeping a considerable time, I find itadvantageous to reheat it after an interval of about twentyfour hours orforty-eight hours from the first heating, the temperature of the vesselor bath being again raised to 212 Fahrenheit and then reduced as rapidlyas possible. Any fresh germs which may have developed in the intervalbetween the first and second heating are hereby destroyed. This processof reheating may be repeated as often as circumstances may require. Incertain states of the weather a lower temperature than 212 Fahrenheitwill suffice, and the periods during which the heat is maintained mayalso be varied.

Before commencing operation the apparatus, bottles, and otherreceptacles should be sterilized.

What I claim as my invention, and desire to secure by Letters Patent, is

1. The improved process of aerating and preserving milk, substantiallyas herein described, consisting in partially sterilizing skimmed orseparated milk by heating it to a temperature of 150 to 160 Fahrenheitcooling the same to about 40 Fahrenheit by means of a coil immersed inice; sterilizing the aerating-gas by causing the same to pass throughaheated coil in a closed chamber,then through a coil submerged in coldwater, then passing the gas through a bath of sterilized watercontaining a flavoring-essence; charging the partially-sterilized milkwith the sterilized gas, bottling the aerated mixture, subjecting thebottled mixture in a closed vessel for about one hour to a temperatureof 150 to 212 Fahrenheit and then rapidly cooling the same; a sterilizedaerated beverage being thus obtained.

2. In the process of aerating and preserving milk, passing theaerating-gas through a heated coil in a closed chamber, then through acoil submerged in cold water, then through a bath of sterilized water,substantially as set forth.

3. In the process of aerating and preserving milk, sterilizing andflavoring the aeratinggas and partially sterilizing the milk, thencharging the latter with the sterilized gas, substantially as set forth.

RICHARD GRAINGER NASH.

